In the conventional technique of providing eyeglasses, the joining and articulation of the temples to the end pieces of the front of the eyeglass frame for supporting the lenses is done by way of alignment of the eyelets provided at the ends of the temples with the eyelets provided at the ends of the front, so as to be able to insert a pin or a screw therein which thus joins the ends in a stable and articulated manner, thus allowing the opening and closing of the temples of the eyeglasses to be worn.
With respect to this conventional solution, the introduction of elasticized hinges, the function of which is to render the use of the eyeglasses more comfortable, while also providing for innumerable construction variations of greater or lesser complexity of the hinge elements for the temples and end pieces of the front or lug of eyeglasses, are all substantially based on the presence of an elastic means, generally acting by traction, with a screw or pin for hingeing the respective eyelets, for example according to the following patents: no. EP0096928 of 1983 in the name of COMET; no. EP0262099 of 1987 in the name of SAFILO; no. EP0395939 of 1990 in the name of OBE WERK; no. EP1556729 of 2003 in the name of IRIDE.
A more recent technique offers the possibility of obtaining a similar elasticity of the temple, by fitting its hingeing end with a flexible plate or end, which can be placed in abutment against a squared abutment that is integral with the end piece of the front of an eyeglass frame, for example according to patent no. IT 1,307,972 of 1999 in the name of Tabacchi, or according to utility model no. DE10 200454841 of 2004 in the name of Frost Paris, or according to utility model no. DE 10 2005034885 of 2005 in the name of Ic! Berlin, and also patent application no. US 2007/0121060 of 2006 in the name of Habermann. In these patents, a part of the temple end is forcibly brought into contact with a squared end of the front of the eyeglass frame, and it can slip along two surfaces of that end which are indicatively mutually perpendicular, thus causing a click that tends to preferably put that temple in the closed and open positions, even in the event that it is splayed open beyond the normal extent.
However, in their practical implementation, even these solutions have been found to be rather impractical and not straightforward to carry out, as well as being complex at assembly time, with frequent problems of wear of the chrome-plated part of the frame and of deficiencies in retaining the lenses. Furthermore, the various solutions known up to now always involve the application of at least one hingeing screw or pin, as well as the usual soldering of the eyelets and the mechanical application of the elastic means, in order to provide the opening and closing click, and these are always provided in seats that are small and inconvenient, which weaken the structure of the eyeglass frame and make it possible to use elastic means of low force that lose their force over time.